In gas turbine engines, it is known to use the bleed flow of the compressor section as the main source for anti-icing airflow, for example by modulating a mix between bleed air from low and high pressure portions of the compressor section. Anti-icing systems have minimum pressure and temperature requirements which for some engines can represent a significant part of the available bleed air, which may be detrimental to the other aircraft bleed air uses such as pressurized cabin air. Accordingly, smaller engines are often not adapted to provide anti-icing airflow, and in aircraft using such engines anti-icing is performed through other means, such as expandable bladders provided on the surfaces susceptible to icing. These other systems may represent undesirable costs and/or maintenance requirements.